1. Field of the Invention
This invention relates to an electrical connector having terminals for soldered connection to a printed circuit board, whereby the terminals have a sealing material deposited thereon for preventing solder and flux wicking into contact portions of the terminal.
2. Description of the Prior Art
Solder wicking is a well known problem in the electrical industry, whereby during the soldering process of electrical contacts to printed circuit boards, the molten solder and flux flows up contact tails of the terminals due to the surface tension (i.e. capillary effect).
A number of solutions have been found to address this problem, for example as shown in U.S. Pat. No. 3,989,331 whereby the contact tail has a kink, or has a material deposited therearound to repel the solder and flux. Unfortunately for some applications, for example if the terminals are to be mounted in a connector, it may not be appropriate to have a kink therein, because the connector housing cavity must be made larger for passage of the kink which also makes sealing of the connector more difficult. The latter also increases the inaccuracy of alignment of the terminal with respect to the PCB. Application of the solder repellent is an expensive process and does not guarantee that solder doesn't flow therepast in all circumstances. Another example is shown in U.S. Pat. No. 4,976,634, whereby a sealing material is placed around contact tails of terminals proximate a mounting face of the connector. This is however a relatively expensive procedure as the sealing material must be applied to the assembled connector from the mounting face, whereby measures must be taken to prevent the sealing material from flowing into the contact area of the connector whilst nevertheless filling all the gaps between the terminal and connector housing. The latter reference has the advantage over the former reference in that the sealing material not only prevents wicking of the solder, but also seals the connector from the environment.
It would be desirable, to provide an electrical connector for soldered connection to a printed circuit board, that is sealed and overcomes the above mentioned problems.